config: Update KP's imx53 HSC config to pass key pressed information

The information about pressed key is relevant in performing correct
update and recovery scenarios via USB pendrive.

This commit modifies envs to provide it.

Signed-off-by: Lukasz Majewski <lukma@denx.de>

include/configs/kp_imx53.h

@@ -44,6 +44,7 @@
 	"updargs=setenv bootargs console=${console} ${smp} ${displayargs}\0" \
 	"initrd_ram_dev=/dev/ram\0" \
 	"addswupdate=setenv bootargs ${bootargs} root=${initrd_ram_dev} rw\0" \
+	"addkeys=setenv bootargs ${bootargs} di=${dig_in} key1=${key1}\0" \
 	"loadusb=usb start; " \
 	       "fatload usb 0 ${loadaddr} ${upd_image}\0" \
 	"up=if tftp ${loadaddr} ${uboot_file}; then " \
@@ -62,6 +63,7 @@
 	       "run updargs; " \
 	       "run addinitrd; " \
 	       "run addswupdate; " \
+	       "run addkeys; " \
 	       "run loadusb; " \
 	       "bootm ${loadaddr}#${fit_config}\0" \
 	BOOTENV